Description Veeder-Root 794380-208 TLS Piping Sump Sensor is an positive alarm indication of any liquid in UST (Underground Storage Tank) sump. It can detect the presence of liquid in a UST sump. Liquid presence could mean a dangerous line leak. When the sensor detects liquid, it sends an alarm signal to the TLS console monitor, where both visual and audible built-in alarm indicators immediately identify the location of the problem. This sump can help you prevent a seroius line leak.